Provide music functions property-{override,revert,set,unset}

Provide music functions property-{override,revert,set,unset}

The previous music functions `override' and `revert' (intentionally
colliding with the respective keywords) are removed.  It would have been
too confusing to have collisions for `set' and `unset' as well which are
just too similar to existing Scheme constructs.

A convert-ly rule for the previous calls override/revert is not
attempted: they have not yet been documented and have been available
only for one unstable version.  Whoever happened to use them already is
capable of replacing them.

Provide check-context-path function

[dak, 2015-07-12 22:46:07]

Well, the consideration for choosing a hyphenated name here instead of camel
case (namely property-override instead of propertyOverride) was that the main
usage was from Scheme anyway.  But since it is a proper music function
nevertheless, I now tend to think that I should not diverge from the normal
naming scheme and change that to propertyOverride etc.  Yes, it will look a bit
out of place in Scheme code but so do all the other music functions consisting
of more than one word.  So I'll be uploading an appropriately changed version
next.

[dak, 2015-07-12 23:19:29]

property-override etc -> propertyOverride etc

[benko.pal, 2015-07-13 06:15:25]

that's fabulous, thanks!

[dak, 2015-07-13 07:50:04]

On 2015/07/13 06:15:25, benko.pal wrote:
> that's fabulous, thanks!

I'd have considered this issue on the level of throwing away the already
finished but rather fragile front hubcaps on a significantly remodeled car and
making a more robust set of all four.  I'm not particularly excited about the
hubcaps but the old design would likely have become a source of embarrassment
eventually.

This approach is not as audacious as the first design (music functions called
"override" and "revert") but quite less likely to fall off.

So this is sort of chasing the fabulosity elsewhere.  I am pretty thrilled about
where it will come together eventually.

[dak, 2015-07-13 18:51:55]

Add forgotten (*location*) arguments to check-context-path